It does charge both phone and battery case at same time... this case has great almost perfect reviews at Amazon..
"I finally got this case after almost three months of wait, they seemed to get a lot of inceptions from Apples with the licensing processes (got all the emails from them), but I decided to wait because I been using their DX Plus for my iPhone 4 (work phone) and it is working very well.
It has been only a week or so and I am very satisfied with this new DX case they have, here are the pros and cons:
Well made, comfortable matte black finishing and sleek
Fits iphone 5 very well
Cable charges case & phone at once
iPhone syncs OK with PC with case on
Adds bulk (I don't mind, actually easier to hold)
Doesn't use Apple cable
Reduces reception slightly
If you are looking for a quality product, this would be the one you are looking for"